$\dfrac{7}{6} - \dfrac{9}{8} = {?}$
Answer: $ = {\dfrac{7 \times 4}{6 \times 4}} - {\dfrac{9 \times 3}{8 \times 3}} $ $ = {\dfrac{28}{24}} - {\dfrac{27}{24}} $ $ = \dfrac{{28} - {27}}{24} $ $ = \dfrac{1}{24}$